Head mounted display device and control method for head mounted display device

ABSTRACT

A transmission type head mounted display device includes an image display unit including an image-light generating unit configured to generate image light on the basis of image data and emit the image light, the image display unit causing a user to visually recognize the image light as a virtual image and transmitting an outside scene in a state in which the image display unit is worn on the head of the user, and a control unit configured to set, as the image light that the control unit causes the user to visually recognize using the image display unit, specific image light generated on the basis of set specific image data and changing according to elapse of time.

BACKGROUND

1. Technical Field

The present invention relates to a head mounted display device.

2. Related Art

A head mounted display device (a head mounted display; HMD), which is adisplay device mounted on the head, is known. For example, the headmounted display device generates, using a liquid crystal display and alight source, image light representing an image and guides the generatedimage light to the eyes of a user using a projection optical system anda light guide plate to thereby cause the user to visually recognize avirtual image. As the head mounted display device, there are two types:a transmission type for enabling the user to visually recognize anoutside scene in addition to the virtual image and a non-transmissiontype for disabling the user from visually recognizing the outside scene.As the transmission type head mounted display device, there are anoptical transmission type and a video transmission type.

JP-A-2010-141548 (Patent Literature 1) discloses an image display devicethat classifies a plurality of frames, which form a received videosignal, respectively into several types according to luminance andchroma and, when changes from a specific type of frames to the othertypes of frames occur a fixed number of times or more in a predeterminednumber of frames, deletes several frames from the predetermined numberof frames to reduce the changes of the types of the frames to therebyreduce the burden on a user who visually recognizes a video.

The related art is also disclosed in “Research Report concerning theInfluence of Contents on the Living Organism, March 2004, Ministry ofInternal Affairs and Communications” (Non Patent Literature 1) and“Guideline by Video Method such as Animation, 2006, Japan BroadcastingCorporation, National Association of Commercial Broadcasters in Japan”(Non Patent Literature 2).

However, in the technique described in Patent Literature 1, the types ofthe respective plurality of frames, which form the received videosignal, are identified and the changes from a specific type of frames tothe other types of frames are reduced. Therefore, a certain effect isobtained concerning only a video visually recognized by the user.However, for example, it is not taken into account to cause the user tovisually recognize a still image without a change in types of frames.Therefore, it is desired to reduce the burden on the user concerning thestill image and the like other than the video. In the transmission typehead mounted display device, a transmitted outside scene is superimposedon a received video to cause the user to visually recognize the outsidescene in addition to the video. Therefore, it is desired to control,taking into account the transmitted outside scene, a virtual image thatthe user is caused to visually recognize. It is also desired to control,according to detected information included in the transmitted outsidescene, the virtual image that the user is caused to visually recognize.Besides, in the head mounted display device in the past, improvement ofconvenience and the like are desired.

SUMMARY

An advantage of some aspects of the invention is to solve at least apart of the problems described above, and the invention can beimplemented as the following aspects.

(1) An aspect of the invention provides a transmission type head mounteddisplay device. The head mounted display device includes: an imagedisplay unit including an image-light generating unit configured togenerate image light on the basis of image data and emit the imagelight, the image display unit causing a user to visually recognize theimage light as a virtual image and transmitting an outside scene in astate in which the image display unit is worn on the head of the user;and a control unit configured to set, as the image light that thecontrol unit causes the user to visually recognize using the imagedisplay unit, specific image light generated on the basis of setspecific image data and changing according to elapse of time. With thehead mounted display device according to this aspect, since the imagelight visually recognized by the user gently changes according to theelapse of time, the burden on the visual sense of the user is reduced.

(2) The head mounted display device according to the aspect describedabove may be configured such that the specific image data is set on thebasis of specific information, the specific image light includes aplurality of kinds of first image light and second image light differentfrom the plurality of kinds of first image light, and the control unitchanges the image light, which the control unit causes the user tovisually recognize using the image display unit, from the plurality ofkinds of first image light to the second image light according to theelapse of time. The head mounted display device according to this aspectcauses the user to visually recognize the second image light aftercausing the user to visually recognize the plurality of kinds of firstimage light according to the elapse of time rather than causing the userto suddenly visually recognize the second image light in a state inwhich only the outside scene is visually recognized. Therefore, sincechanges of the outside scene and the image light visually recognized bythe user are gentle, it is possible to further reduce the burden on thevisual sense of the user.

(3) The head mounted display device according to the aspect describedabove may be configured such that each of the plurality of kinds offirst image light and the second image light have different luminances.With the head mounted display device according to this aspect, it ispossible to generate the plurality of kinds of first image light and thesecond image light on the basis of one image data simply by controllingthe luminances. Therefore, it is possible to reduce the burden on thevisual sense of the user with simple control.

(4) The head mounted display device according to the aspect describedabove may be configured such that the image-light generating unit isconfigured by an image modulation element capable of adjusting an amountof light to be emitted, and the control unit adjusts the luminances ofeach of the plurality of kinds of first image light and the second imagelight to be different by adjusting the amount of light emitted from theimage modulation element. With the head mounted display device accordingto this aspect, it is possible to generate the plurality of kinds offirst image light and the second image light on the basis of one imagedata simply by controlling the luminances. Therefore, it is possible toreduce the burden on the visual sense of the user with simple control.

(5) The head mounted display device according to the aspect describedabove may be configured such that the image-light generating unitincludes a light source capable of adjusting an amount of light to beemitted and an image formation panel configured to convert the lightemitted from the light source into the image light, and the control unitadjusts the luminances of each of the plurality of kinds of first imagelight and the second image light to be different by adjusting the amountof the light emitted from the light source. With the head mounteddisplay device according to this aspect, it is possible to generate theplurality of kinds of first image light and the second image light onthe basis of one image data simply by controlling the luminances.Therefore, it is possible to reduce the burden on the visual sense ofthe user with simple control.

(6) The head mounted display device according to the aspect describedabove may be configured such that the luminance of the second imagelight is larger than the luminance of each of the plurality of kinds offirst image light, and the control unit causes, using the image displayunit, when the control unit changes a state in which the control unitdoes not cause the user to visually recognize the plurality of kinds offirst image light or the second image light to a state in which thecontrol unit causes the user to visually recognize the second imagelight after causing the user to visually recognize the plurality ofkinds of first image light, the user to visually recognize the pluralityof kinds of first image light as if the luminance of the plurality ofkinds of first image light increases according to the elapse of time andcauses, when the control unit changes a state in which the control unitcauses the user to visually recognize the plurality of kinds of firstimage light after causing the user to visually recognize the secondimage light to the state in which the control unit does not cause theuser to visually recognize the plurality of kinds of first image lightor the second image light, the user to visually recognize the pluralityof kinds of first image light as if the luminance decreases according tothe elapse of time. With the head mounted display device according tothis aspect, it is possible to cause the user to visually recognize theplurality of kinds of first image light and the second image light as ifthe second image light gradually emerges through the plurality of kindsof first image light. It is possible to further reduce the burden on thevisual sense sight of the user.

(7) The head mounted display device according to the aspect describedabove may be configured such that the control unit causes, using theimage display unit, when the control unit changes the state in which thecontrol unit does not cause the user to visually recognize the pluralityof kinds of first image light or the second image light to the state inwhich the control unit causes the user to visually recognize the secondimage light after causing the user to visually recognize the pluralityof kinds of first image light, the user to visually recognize theplurality of kinds of first image light as if an increase ratio of theluminance of the plurality of kinds of first image light increasesaccording to the elapse of time and causes, when the control unitchanges the state in which the control unit causes the user to visuallyrecognize the plurality of kinds of first image light after causing theuser to visually recognize the second light to the state in which thecontrol unit does not cause the user to visually recognize the pluralityof kinds of first image light or the second image light, the user tovisually recognize the plurality of kinds of first image light as if adecrease ratio of the luminance increases according to the elapse oftime. With the head mounted display device according to this aspect, itis possible to cause the user to visually recognize the plurality ofkinds of first image light and the second image light as if the secondimage light gradually emerges through the plurality of kinds of firstimage light. It is possible to further reduce the burden on the visualsight of the user.

(8) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a pupil specifying unit configured to specify the sizeof the pupils of the user, and the control unit sets the luminances ofeach of the plurality of kinds of first image light and the second imagelight such that luminance at the time when the specified size of thepupils is a second size larger than a first size is smaller thanluminance at the time when the specified size of the pupils is the firstsize. With the head mounted display device according to this aspect,when the size of the pupils of the eyes of the user is large, that is,brightness around the user is low, control for reducing the luminancesof the plurality of kinds of first image light and the second imagelight is performed. When the brightness around the user is high, controlfor increasing the luminances of the plurality of kinds of first imagelight and the second image light is performed. Therefore, the luminancesof the plurality of kinds of first image light and the second imagelight are controlled according to the brightness around the user.Therefore, it is possible to reduce the visual burden on the userwithout causing the user to visually recognize image light withluminance higher than necessary. Further, it is possible to cause theuser to visually recognize image light having brightness enough for theuser to visually recognize the image light.

(9) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a pupil specifying unit configured to specify the sizeof the pupils of the user, and the control unit sets time for changingthe plurality of kinds of first image light to the second image lightlonger as the specified size of the pupils is larger when the controlunit changes a state in which the specific image light is not visuallyrecognized by the user to a state in which the specific image light isvisually recognized by the user. With the head mounted display deviceaccording to this aspect, when the size of the pupils of the eyes of theuser is large, that is, brightness around the user is low, in order toprevent the visual burden on the user from increasing when the controlunit causes the user to visually recognize the plurality of kinds offirst image light and the second image light, the time for changing theplurality of kinds of first image light to the second image light is setlong. Therefore, it is possible to reduce the visual burden on the user.

(10) The head mounted display device according to the aspect describedabove may be configured such that each of the plurality of kinds offirst image light is a part of the second image light, and the controlunit causes, using the image display unit, when the control unit changesa state in which the control unit does not cause the user to visuallyrecognize the plurality of kinds of first image light or the secondimage light to a state in which the control unit causes the user tovisually recognize the second image light after causing the user tovisually recognize the plurality of kinds of first image light, the userto visually recognize the plurality of kinds of first image light as ifthe size of the plurality of kinds of first image light increasesaccording to the elapse of time and causes, when the control unitchanges a state in which the control unit causes the user to visuallyrecognize the plurality of kinds of first image light after causing theuser to visually recognize the second image light to the state in whichthe control unit does not cause the user to visually recognize theplurality of kinds of first image light or the second image light, theuser to visually recognize the plurality of kinds of first image lightas if the size of the plurality of kinds of first image light decreasesaccording to the elapse of time. The head mounted display deviceaccording to this aspect increases a region of an image to be visuallyrecognized according to the elapse of time rather than causing the userto suddenly visually recognize the second image light in a state inwhich only the outside scene is visually recognized. Therefore, sincechanges of the outside scene and the image visually recognized by theuser are gentle, the burden on the visual sense of the user is reduced.

(11) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a temperature detecting unit configured to detect atemperature distribution of the outside scene in a visual line directionof the user, and the specific information includes information forspecifying the detected temperature distribution of the outside scene.With the head mounted display device according to this aspect, it ispossible to cause the user to visually recognize an image involved in atemperature change of the outside scene. Therefore, convenience for theuser is improved.

(12) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes: an image pickup unit configured to pick up an image ofthe outside scene in a visual line direction of the user; and a targetextracting unit configured to extract a specific target included in thepicked-up image, and the specific information is information concerningthe extracted specific target. With the head mounted display deviceaccording to this aspect, it is possible to control, according to adetection result of the specific target included in the picked-up image,an image that the user is caused to visually recognize. Therefore,convenience for the user is improved.

(13) The head mounted display device according to the aspect describedabove may be configured such that the target extracting unit specifiesspeed of a movement of the specific target in an image pickup range ofthe image pickup unit, and the control unit sets time for changing theplurality of kinds of first image light to the second image light longeras the specified speed of the movement of the specific target is higher.With the head mounted display device according to this aspect, when thespeed of the movement of the specific target is high, the time forchanging the plurality of kinds of first image light to the second imagelight is set long. Therefore, it is possible to reduce the visual burdenon the user by reducing a visual change to the user.

(14) The head mounted display device according to the aspect describedabove may be configured such that the target extracting unit specifiesspeed of a movement of the specific target in an image pickup range ofthe image pickup unit, and, when the specified speed of the specifictarget is equal to or higher than a set first threshold, the controlunit sets, as the image light that the control unit causes the user tovisually recognize using the image display unit, pre-display image lightgenerated on the basis of image data different from the specific imagelight before setting the specific image light. Even when the specifictarget is included in the image pickup range, when the speed of themovement of the specific target is high, the head mounted display deviceaccording to this aspect causes the user to visually recognize theplurality of kinds of first image light in a preparation stage beforecausing the user to visually recognize the second image light.Therefore, it is possible to reduce a change in the outside scenevisually recognized by the user and reduce the visual burden on theuser.

(15) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a distance specifying unit configured to specify adistance between the specific target and the image display unit, and thecontrol unit sets the specific image light when the specified distanceis equal to or smaller than a set second threshold. With the headmounted display device according to this aspect, an image of thespecific target is picked up and, in addition, only when the distancebetween the user and the specific target is equal to or smaller than afixed distance, the plurality of kinds of first image light and thesecond image light are visually recognized by the user. Therefore, whenthe specific target is not present in a position close to the user, thesecond image light based on information unnecessary for the user is notvisually recognized by the user. Therefore, convenience for the user isimproved.

(16) The head mounted display device according to the aspect describedabove may be configured such that the specific information isinformation concerning an operation that the user should perform for thespecific target. With the head mounted display device according to thisaspect, the user can perform the operation safely and in a correctprocedure. Therefore, convenience for the user is improved.

(17) In the head mounted display device according to this aspect, thehead mounted display device may further include a position-informationacquiring unit configured to acquire position information for specifyinga position of the user, and the specific information may include theacquired position information. With the head mounted display deviceaccording to this aspect, it is possible to control an image, which theuser is caused to visually recognize, on the basis of the positioninformation of the user. Therefore, convenience for the user isimproved.

(18) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a visual-line-direction specifying unit configured toacquire visual line direction information, which is information forspecifying a visual line direction of the user, and the specificinformation includes the visual line direction information. With thehead mounted display device according to this aspect, when the visualline direction of the user is not fixed, the user is not caused tovisually recognize the plurality of kinds of first image light or thesecond image light. Therefore, even if the user changes the visual linedirection, the transmitted outside scene only changes. The user does nothave to visually recognize a generated image. Therefore, there is littlechange in the outside scene visually recognized by the user. The burdenon the visual sense of the user is further reduced.

(19) The head mounted display device according to the aspect describedabove may be configured such that the head mounted display devicefurther includes a movement specifying unit configured to specify speedof a movement of the user, and the control unit sets time for changingthe plurality of kinds of first image light to the second image lightlonger as the specified speed of the movement of the specific target ishigher. With the head mounted display device according to this aspect,when the speed of the movement of the user is high, the control unitsets the time for changing the plurality of kinds of first image lightto the second image light long. Consequently, when the movement of theuser is fast, a ratio of a change of the plurality of kinds of firstimage light visually recognized by the user is small. Therefore, it ispossible to reduce the visual burden on the user.

Not all of a plurality of components of the aspects of the inventionexplained above are essential. To solve a part or all of the problems orto attain a part or all of the effects described in this specification,concerning a part of the plurality of components, it is possible toperform, as appropriate, change, deletion, replacement with new othercomponents, and deletion of a part of limited contents. To solve a partor all of the problems or to attain a part or all of the effectsdescribed in this specification, it is also possible to combine apart orall of technical features included in one aspect of the invention with apart or all of technical features included in the other aspects of theinvention to form independent one aspect of the invention.

For example, one aspect of the invention can be realized as a deviceincluding at least one or more or all of the image display unit and thecontrol unit. That is, the device may include or may not include theimage display unit. The device may include or may not include thecontrol unit. The image display unit may include, for example, animage-light generating unit configured to generate image light on thebasis of image data and emit the image light. The image display unit maycause a user to visually recognize the image light as a virtual imageand transmit an outside scene in a state in which the image display unitis worn on the head of the user. The control unit may set, as the imagelight that the control unit causes the user to visually recognize usingthe image display unit, specific image light generated on the basis ofset specific image data and changing according to elapse of time. Thedevice can be realized as, for example, a head mounted display deviceand can also be realized as devices other than the head mounted displaydevice. According to such an aspect, it is possible to attain at leastone of various objects such as improvement of operability andsimplification of the device, integration of the device, and improvementof convenience for the user who uses the device. A part or all of thetechnical features of the aspects of the head mounted display deviceexplained above can be applied to the device.

The invention can be realized in various forms other than the headmounted display device. The invention can be realized in forms such as adisplay device, a control method for the head mounted display device andthe display device, a head mounted display system, a computer programfor realizing functions of the head mounted display system, the displaydevice, and a recording medium having recorded therein the computerprogram, and a data signal including the computer program and embodiedin a carrier wave.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is an explanatory diagram showing the external configuration of ahead mounted display device.

FIG. 2 is a block diagram schematically showing the configuration of thehead mounted display device.

FIG. 3 is an explanatory diagram showing a state in which image light isemitted by an image-light generating unit.

FIG. 4 is an explanatory diagram showing a flow of specific imagedisplay processing.

FIG. 5 is an explanatory diagram showing an example of a selection menuscreen visually recognized by a user.

FIG. 6 is an explanatory diagram showing an example of a specific imagevisually recognized by the user.

FIG. 7 is an explanatory diagram showing an example of an intermediateimage visually recognized by the user.

FIG. 8 is an explanatory diagram showing an example of temporaltransition of the luminance of backlights in image display processing.

FIG. 9 is an explanatory diagram showing a flow of specific imagenon-display processing.

FIG. 10 is an explanatory diagram showing an example of temporaltransition of the luminance of the backlights in image non-displayprocessing.

FIG. 11 is a block diagram functionally showing the configuration of ahead mounted display device in a second embodiment.

FIG. 12 is an explanatory diagram showing a flow of specific imagedisplay processing in the second embodiment.

FIG. 13 is an explanatory diagram showing an example of an advancenotice image visually recognized by a user.

FIG. 14 is an explanatory diagram of an example of a specific imagevisually recognized by the user.

FIG. 15 is an explanatory diagram showing the external configuration ofa head mounted display device in a third embodiment.

FIG. 16 is a block diagram functionally showing the configuration of thehead mounted display device in the third embodiment.

FIG. 17 is an explanatory diagram showing a flow of specific imagedisplay processing in the third embodiment.

FIG. 18 is an explanatory diagram showing the flow of the specific imagedisplay processing in the third embodiment.

FIG. 19 is an explanatory diagram showing an example of temporaltransition of the luminance of backlights in image display processing.

FIG. 20 is an explanatory diagram showing an example of a specific imagevisually recognized by a user.

FIG. 21 is an explanatory diagram showing a flow of specific imagechanging processing.

FIG. 22 is an explanatory diagram showing an example of a specific imagevisually recognized by the user after a target image changes.

FIG. 23 is an explanatory diagram showing an example of an intermediateimage visually recognized by the user.

FIG. 24 is an explanatory diagram showing an example of an intermediateimage visually recognized by the user.

FIG. 25 is an explanatory diagram showing an example of an intermediateimage visually recognized by the user.

FIG. 26 is an explanatory diagram showing an example of a specific imagevisually recognized by the user.

FIG. 27 is an explanatory diagram showing an example of a specific imagevisually recognized by the user.

FIG. 28 is an explanatory diagram showing an example of a menu imageincluding a specific image visually recognized by the user.

FIG. 29 is an explanatory diagram showing an example of a specific imagevisually recognized by the user.

FIGS. 30A and 30B are explanatory diagrams showing the externalconfigurations of head mounted display devices in modifications.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention are explained in order described below.

A. First Embodiment

A-1. Configuration of a head mounted display device

A-2. Specific image display processing

A-3. Specific image non-display processing

B. Second Embodiment

C. Third Embodiment

D. Modifications

A-1. Configuration of a Head Mounted Display Device

FIG. 1 is an explanatory diagram showing the external configuration of ahead mounted display device 100. The head mounted display device 100 isa display device mounted on the head and is also called head mounteddisplay (HMD). The head mounted display device 100 in this embodiment isa optical transmission type head mounted display device for enabling auser to visually recognize a virtual image and, at the same time,directly visually recognize an outside scene. In this specification, thevirtual image visually recognized by the user using the head mounteddisplay device 100 is also referred to as “displayed image” forconvenience. Emitting image light generated on the basis of image datais referred to as “display an image”.

The head mounted display device 100 includes an image display unit 20configured to cause a user to visually recognize a virtual image in astate in which the image display unit 20 is worn on the head of the userand a control unit 10 (a controller 10) configured to control the imagedisplay unit 20.

The image display unit 20 is a wearing body worn on the head of the userand has an eyeglass shape in this embodiment. The image display unit 20includes a right holding unit 21, a right display driving unit 22, aleft holding unit 23, a left display driving unit 24, a rightoptical-image display unit 26, a left optical-image display unit 28, anda thermography 62. The right optical-image display unit 26 and the leftoptical-image display unit 28 are respectively arranged to be located infront of the right and left eyes of the user when the user wears theimage display unit 20. One end of the right optical-image display unit26 and one end of the left optical-image display unit 28 are connectedto each other in a position corresponding to the middle of the foreheadof the user when the user wears the image display unit 20.

The right holding unit 21 is a member provided to extend from an end ER,which is the other end of the right optical-image display unit 26, to aposition corresponding to the temporal region of the user when the userwears the image display unit 20. Similarly, the left holding unit 23 isa member provided to extend from an end EL, which is the other end ofthe left optical-image display unit 28, to a position corresponding tothe temporal region of the user when the user wears the image displayunit 20. The right holding unit 21 and the left holding unit 23 hold theimage display unit 20 on the head of the user in the same manner astemples of eyeglasses.

The right display driving unit 22 and the left display driving unit 24are arranged on sides opposed to the head of the user when the userwears the image display unit 20. In the following explanation, the rightholding unit 21 and the left holding unit 23 are generally simplyreferred to as “holding unit” as well. The right display driving unit 22and the left display driving unit 24 are generally simply referred to as“display driving unit” as well. The right optical-image display unit 26and the left optical-image display unit 28 are generally simply referredto as “optical-image display unit” as well.

The display driving units 22 and 24 include liquid crystal displays 241and 242 (hereinafter referred to as “LCDs 241 and 242”) and projectionoptical systems 251 and 252 (see FIG. 3). Details of the configurationof the display driving units 22 and 24 are explained below. Theoptical-image display units 26 and 28 functioning as optical membersinclude light guide plates 261 and 262 (see FIG. 2) and dimming plates.The light guide plates 261 and 262 are formed of a light transmissiveresin material or the like and guide image lights output from thedisplay driving units 22 and 24 to the eyes of the user. The dimmingplates are thin plate-like optical elements and arranged to cover thefront side of the image display unit 20, which is a side opposite to theeye side of the user. The dimming plates protect the light guide plates261 and 262 and suppress damage, adhesion of stain, and the like to thelight guide plates 261 and 262. By adjusting the light transmittance ofthe dimming plates, it is possible to adjust an amount of external lightentering the eyes of the user and adjust easiness of visual recognitionof a virtual image. Note that the dimming plates can be omitted.

The thermography 62 is arranged in a position corresponding to themiddle of the forehead of the user when the user wears the image displayunit 20. The thermography 62 is an infrared thermography that detects aninfrared ray radiated from an object and different depending ontemperature, converts a detected infrared energy amount intotemperature, and generates a temperature distribution image (an infraredheat image) representing a distribution of temperature. An angle of viewof the thermography 62 is set such that a region of an image to bepicked up is the same as a visual line of the user who wears the imagedisplay unit 20. The thermography 62 is equivalent to a temperaturedetecting unit in the appended claims.

The image display unit 20 further includes a connecting unit 40 forconnecting the image display unit 20 to the control unit 10. Theconnecting unit 40 includes a main body cord 48 connected to the controlunit 10, a right cord 42 and a left cord 44, which are two cordsbranching from the main body cord 48, and a coupling member 46 providedat a branching point. The right cord 42 and the left cord 44 are twocords branching from the main body cord 48. The right cord 42 isinserted into a housing of the right holding unit 21 from a distal endportion AP in an extending direction of the right holding unit 21 andconnected to the right display driving unit 22. Similarly, the left cord44 is inserted into a housing of the left holding unit 23 from a distalend portion AP in an extending direction of the left holding unit 23 andconnected to the left display driving unit 24. The coupling member 46 isprovided at a branching point of the main body cord 48 and the right andleft cords 42 and 44. The coupling member 46 includes a jack forconnecting an earphone plug 30. A right earphone 32 and a left earphone34 extend from the earphone plug 30.

The image display unit 20 and the control unit 10 perform transmissionof various signals via the connecting unit 40. Connectors (not shown inthe figure), which fit with each other, are respectively provided at anend of the main body cord 48 on the opposite side of the coupling member46 and in the control unit 10. The control unit 10 and the image displayunit 20 are connected and disconnected according to fitting andunfitting of the connector of the main body cord 48 and the connector ofthe control unit 10. For example, a metal cable or an optical fiber canbe adopted as the right cord 42, the left cord 44, and the main bodycord 48.

The control unit 10 is a device for controlling the head mounted displaydevice 100. The control unit 10 includes a determination key 11, alighting unit 12, a display switching key 13, a track pad 14, aluminance switching key 15, a direction key 16, a menu key 17, and apower switch 18. The determination key 11 detects pressing operation andoutputs a signal for determining content of operation by the controlunit 10. The lighting unit 12 notifies, with a light emission statethereof, an operation state of the head mounted display device 100. Asthe operation state of the head mounted display device 100, for example,there are ON/OFF of a power supply. As the lighting unit 12, forexample, an LED (Light Emitting Diode) is used. The display switchingkey 13 detects pressing operation and outputs, for example, a signal forswitching a display mode of a content moving image to 3D and 2D. Thetrack pad 14 detects operation by a finger of the user on an operationsurface of the track pad 14 and outputs a signal corresponding todetected content. As the track pad 14, various track pads such as anelectrostatic type, a pressure detection type, and an optical type canbe adopted. The luminance switching key 15 detects pressing operationand outputs a signal for increasing and decreasing the luminance of theimage display unit 20. The direction key 16 detects pressing operationfor keys corresponding to up, down, left, and right directions andoutputs a signal corresponding to detected content. The power switch 18detects slide operation of the switch to switch a state of a powersupply of the head mounted display device 100.

FIG. 2 is a block diagram functionally showing the configuration of thehead mounted display device 100. As shown in FIG. 2, the control unit 10includes an input-information acquiring unit 110, a storing unit 120, apower supply 130, an operation unit 135, a CPU 140, an interface 180,and transmitting units (Tx) 51 and 52. The operation unit 135 receivesoperation by the user. The operation unit 135 is configured by thedetermination key 11, the display switching key 13, the track pad 14,the luminance switching key 15, the direction key 16, the menu key 17,and the power switch 18.

The input-information acquiring unit 110 acquires a signal correspondingto an operation input by the user. As the signal corresponding to theoperation input, for example, there are operation inputs to the trackpad 14, the direction key 16, and the power switch 18 arranged on theoperation unit 135. The power supply 130 supplies electric power to theunits of the head mounted display device 100. As the power supply 130,for example, a secondary battery can be used. The storing unit 120stores therein various computer programs. The storing unit 120 isconfigured by a ROM, a RAM, and the like. The CPU 140 reads out andexecutes the computer programs stored in the storing unit 120 to therebyfunction as an operating system 150 (OS 150), a display control unit190, a sound processing unit 170, an image processing unit 160, avisual-line-direction determining unit 166, and a specific-image controlunit 165.

The display control unit 190 generates control signals for controllingthe right display driving unit 22 and the left display driving unit 24.Specifically, the display control unit 190 individually controls, usingthe control signals, ON/OFF of driving of the right LCD 241 by a rightLCD control unit 211, ON/OFF of driving of a right backlight 221 by aright backlight control unit 201, ON/OFF of driving of the left LCD 242by a left LCD control unit 212, and ON/OFF of driving of a leftbacklight 222 by a left backlight control unit 202. Consequently, thedisplay control unit 190 controls generation and emission of imagelights by the right display driving unit 22 and the left display drivingunit 24. For example, the display control unit 190 causes both of theright display driving unit 22 and the left display driving unit 24 togenerate image lights, causes one of the right display driving unit 22and the left display driving unit 24 to generate image light, or causesboth of the right display driving unit 22 and the left display drivingunit 24 not to generate image light.

The display control unit 190 transmits control signals to the right LCDcontrol unit 211 and the left LCD control unit 212 respectively via thetransmitting units 51 and 52. The display control unit 190 transmitscontrol signals respectively to the right backlight control unit 201 andthe left backlight control unit 202.

The image processing unit 160 acquires an image signal included incontents. The image processing unit 160 separates synchronizationsignals such as a vertical synchronization signal VSync and a horizontalsynchronization signal HSync from the acquired image signal. The imageprocessing unit 160 generates a clock signal PCLK using a PLL (PhaseLocked Loop) circuit or the like (not shown in the figure) according tocycles of the separated vertical synchronization signal VSync andhorizontal synchronization signal HSync. The image processing unit 160converts the analog image signal, from which the synchronization signalsare separated, into a digital image signal using an A/D conversioncircuit or the like (not shown in the figure). Thereafter, the imageprocessing unit 160 stores the digital image signal after the conversionin a DRAM in the storing unit 120 frame by frame as image data (RGBdata) of a target image. The image processing unit 160 may execute imageprocessing such as resolution conversion processing, various kinds oftone correction processing for adjustment of luminance and chroma, andkeystone correction processing on the image data.

The image processing unit 160 transmits the clock signal PCLK, thevertical synchronization signal VSync, and the horizontalsynchronization signal HSync generated by the image processing unit 160and the image data stored in the DRAM in the storing unit 120respectively via the transmitting units 51 and 52. The image datatransmitted via the transmitting unit 51 is referred to as “image datafor right eye” as well. The image data transmitted via the transmittingunit 52 is referred to as “image data for left eye” as well. Thetransmitting units 51 and 52 function as a transceiver for serialtransmission between the control unit 10 and the image display unit 20.

The sound processing unit 170 acquires a sound signal included in thecontents, amplifies the acquired sound signal, and supplies theamplified sound signal to a speaker (not shown) in the right earphone 32or a speaker (not shown) in the left earphone 34 connected to thecoupling member 46. For example, when a Dolby (registered trademark)system is adopted, processing for the sound signal is performed.Different sounds, the frequencies or the like of which are varied, arerespectively output from the right earphone 32 and the left earphone 34.

The visual-line-direction determining unit 166 estimates a visual linedirection of the user on the basis of a direction and a movement of theimage display unit 20 detected by a 9-axis sensor 66 explained below.

The specific-image control unit 165 is a high-heat detection application(hereinafter simply referred to as “heat detection application” as well)for displaying a portion having temperature equal to or higher than athreshold as a specific image. The specific-image control unit 165identifies a region having temperature equal to or higher than thethreshold on the basis of a temperature distribution image acquired bythe thermography 62. The specific-image control unit 165 createsspecific image data indicating a red image in a size same as the size ofthe identified region in order to cause the user to visually recognizethat the temperature is equal to or higher than the threshold. Thespecific-image control unit 165 can create, on the basis of the specificimage data, image data in which the color and the region in the specificimage are changed. The specific-image control unit 165 transmits thecreated specific image data to the image processing unit 160 and thedisplay control unit 190 as a control signal. The specific-image controlunit 165 is equivalent to a control unit in the appended claims.

The interface 180 is an interface for connecting various externalapparatuses OA, which are supply sources of contents, to the controlunit 10. Examples of the external apparatuses OA include a personalcomputer PC, a cellular phone terminal, and a game terminal. As theinterface 180, for example, a USB interface, a micro USB interface, oran interface for a memory card can be used.

The image display unit 20 includes the right display driving unit 22,the left display driving unit 24, the right light guide plate 261functioning as the right optical-image display unit 26, the left lightguide plate 262 functioning as the left optical-image display unit 28,the 9-axis sensor 66, and the thermography 62.

The 9-axis sensor 66 is a motion sensor configured to detectacceleration (three axes), angular velocity (three axes), andterrestrial magnetism (three axes). Since the 9-axis sensor 66 isprovided in the image display unit 20, when the image display unit 20 isworn on the head of the user, the 9-axis sensor 66 detects a movement ofthe head of the user. A direction of the image display unit 20 isspecified from the detected movement of the head of the user. Thevisual-line-direction determining unit 166 specifies a visual linedirection of the user. When detected acceleration and angular velocityare equal to or lower than thresholds, the visual-line-directiondetermining unit 166 determines that the visual line direction of theuser is fixed. The 9-axis sensor 66 and the visual-line-directiondetermining unit 166 are equivalent to a visual-line-directionspecifying unit in the appended claims.

The right display driving unit 22 includes a receiving unit (Rx) 53, theright backlight control unit 201 (right BL control unit 201) and theright backlight 221 (right BL 221) functioning as a light source, theright LCD control unit 211 and the right LCD 241 functioning as adisplay element, and the right projection optical system 251. The rightbacklight control unit 201 and the right backlight 221 function as thelight source. The right LCD control unit 211 and the right LCD 241function as the display element. The right backlight control unit 201,the right LCD control unit 211, the right backlight 221, and the rightLCD 241 are collectively referred to as “image-light generating unit” aswell.

The receiving unit 53 functions as a receiver for serial transmissionbetween the control unit 10 and the image display unit 20. The rightbacklight control unit 201 drives the right backlight 221 on the basisof an input control signal. The right backlight 221 is, for example, alight emitting body such as an LED or an electroluminescence (EL). Theright LCD control unit 211 drives the right LCD 241 on the basis of theclock signal PCLK, the vertical synchronization signal VSync, thehorizontal synchronization signal HSync, and the image data for righteye input via the receiving unit 53. The right LCD 241 is a transmissiveliquid crystal panel on which a plurality of pixels are arranged in amatrix shape.

The right projection optical system 251 is configured by a collimatelens that changes the image light emitted from the right LCD 241 tolight beams in a parallel state. The right light guide plate 261functioning as the right optical-image display unit 26 guides the imagelight output from the right projection optical system 251 to a right eyeRE of the user while reflecting the image light along a predeterminedoptical path. The right projection optical system. 251 and the rightlight guide plate 261 are collectively referred to as “light guide unit”as well.

The left display driving unit 24 includes a configuration same as theconfiguration of the right display driving unit 22. The left displaydriving unit 24 includes a receiving unit 54 (Rx 54), the left backlightcontrol unit 202 (left BL control unit 202) and the left backlight 222(left BL 222) functioning as a light source, the left LCD control unit212 and the left LCD 242 functioning as a display element, and the leftprojection optical system 252. The left backlight control unit 202 andthe left backlight 222 function as the light source. The left LCDcontrol unit 212 and the left LCD 242 function as the display element.The left backlight control unit 202, the left LCD control unit 212, theleft backlight 222, and the left LCD 242 are collectively referred to as“image-light generating unit” as well. The left projection opticalsystem 252 is configured by a collimate lens that changes the imagelight emitted from the left LCD 242 to light beams in a parallel state.The left light guide plate 262 functioning as the left optical-imagedisplay unit 28 guides the image light output from the left projectionoptical system 252 to a left eye LE of the user while reflecting theimage light along a predetermined optical path. The left projectionoptical system. 252 and the left light guide plate 262 are collectivelyreferred to as “light guide unit” as well. The backlight control units201 and 202 and the backlight 221 and 222 are equivalent to a lightsource in the appended claims. The LCD control units 211 and 212 and theLCDs 241 and 242 are equivalent to an image formation panel in theappended claims.

FIG. 3 is an explanatory diagram showing a state in which image light isemitted by the image-light generating unit. The right LCD 241 drivesliquid crystals in the positions of the pixels arranged in the matrixshape to thereby change the transmittance of light transmitted throughthe right LCD 241 to modulate illumination light IL irradiated from theright backlight 221 to effective image light PL representing an image.The same applies to the left side. Although the backlight system isadopted in this embodiment as shown in FIG. 3, the image light may beemitted using a front light system or a reflection system.

A-2. Specific Image Display Processing

FIG. 4 is an explanatory diagram showing a flow of specific imagedisplay processing. In the specific image display processing, after apredetermined detection condition is selected, specific image data iscreated according to the selected detection condition and a specificimage is displayed on the image display unit 20.

In the specific image display processing, first, when the operation unit135 receives predetermined operation, the specific-image control unit165 causes the image display unit 20 to display a selection menu screenfor an application (step S11). FIG. 5 is an explanatory diagram showingan example of a selection menu screen IMG1 visually recognized by theuser. In FIG. 5, a visual field VR visually recognized by the user isshown. An image display largest region PN indicates an outer frame of alargest region in which image light is formed. In FIG. 5, a broken lineof the outer frame of the image display largest region PN is shown forconvenience and is not visually recognized by the user. As shown in FIG.5, in the image display largest region PN, the selection menu screenIMG1 and a cursor CS are shown. Selection buttons for a selectableplurality of applications are included in the selection menu screen IMG1displayed in the image display largest region PN. When the operationunit 135 is operated by the user, the cursor CS moves in the imagedisplay largest region PN. When the determination key 11 is depressed ina state in which the cursor CS overlaps any one of the buttons, thebutton is selected.

After the selection menu screen IMG1 is displayed (step S11 in FIG. 4),when a specific application is selected by the user (step S12:application is selected), the specific-image control unit 165 causes theimage display unit 20 to display a screen corresponding to theapplication selected by the user (hereinafter simply referred to as“selected application”) as well. When the selected application is adetection application, the specific-image control unit 165 causes theimage display unit 20 to display an input screen for a detectioncondition (step S13). When a past history included in the selection menuscreen IMG1 is selected in the processing in step S12 (step S12: historyis selected), the specific-image control unit 165 causes the imagedisplay unit 20 to display selected applications in the past anddetection conditions of the respective selected applications (step S14).In explanation in this embodiment, a heat detection application isselected. In the heat detection application, a setting screen for alower limit temperature to be detected is displayed on the image displayunit 20 as an input screen for a detection condition.

After the processing in step S13 and the processing in step S14, whenthe operation unit 135 is operated by the user, a lower limittemperature, which is a detection condition, is set (step S15). When thelower limit temperature is set, the specific-image control unit 165starts the thermography 62 and the 9-axis sensor 66, which are devicesrelated to the heat detection application (step S16).

Subsequently, the specific-image control unit 165 detects a regionhaving temperature equal to or higher than a threshold satisfying thedetection condition in a temperature distribution image picked up by thethermography 62 (step S17). When a region having temperature equal to orhigher than the threshold is not detected (step S17: NO), thespecific-image control unit 165 continues to monitor a region havingtemperature equal to or higher than the threshold. When a region havingtemperature equal to or higher than the threshold is detected (step S17:YES), the visual-line-direction determining unit 166 determines whethera visual line direction of the user is fixed (step S18).

When it is determined in the processing in step S18 that the visual linedirection of the user is not fixed (step S18: NO), while continuing tomonitor detection of a region having temperature equal to or higher thanthe threshold (step S17), the specific-image control unit 165 waits forthe visual line direction of the user to be fixed (step S18). When it isdetermined in the processing in step S18 that the visual line directionof the user is fixed (step S18: YES), the specific-image control unit165 specifies the region having the temperature equal to or higher thanthe threshold as a position where the specific image is displayed (stepS19). In a state in which the region having the temperature equal to orhigher than the threshold is detected, in some case, the visual linedirection of the user is not fixed. Therefore, when the region havingthe temperature equal to or higher than the threshold is detected andthe visual line direction of the user is fixed, the region having thetemperature equal to or higher than the threshold is specified.

When the region having the temperature equal to or higher than thethreshold is specified (step S19), the specific-image control unit 165sets specific image data corresponding to the specified region (stepS20). FIG. 6 is an explanatory diagram showing an example of a specificimage visually recognized by the user. In FIG. 6, the visual field VRvisually recognized by the user is shown. In FIG. 6, a specific imageSI1 and a specific image SI2 displayed in the image display largestregion PN and generated on the basis of the specific image data(hereinafter collectively referred to as “specific images SI1 and SI2”as well) are shown. The specific image SI1 is an image showing theregion having the temperature equal to or higher than the thresholddetected by the thermography 62. The specific image SI2 is a messageimage for informing the user that the region indicated by the specificimage I1 has the temperature equal to or higher than the threshold andis dangerous because of the high temperature.

When the specific image data is set (step S20 in FIG. 4), thespecific-image control unit 165 generates a specific image and aplurality of intermediate images on the basis of the set specific imagedata and causes the image display unit 20 to display the specific imageand a plurality of intermediate images (step S21). FIG. 7 is anexplanatory diagram showing an example of an intermediate image visuallyrecognized by the user. In FIG. 7, an intermediate image MI1 and anintermediate image MI2 displayed in the image display largest region PN(hereinafter collectively referred to as “intermediate images MI1 andMI2” as well) are shown. The intermediate image MI1 is an image showingthe region having the temperature equal to or higher than the thresholddetected by the thermography 62, that is, a region same as the specificimage SI1. The intermediate image MI2 is an image showing a region sameas the specific image SI2. In FIGS. 6 and 7, the thickness of a color ofan image corresponding to luminance is indicated by the thickness ofhatching.

The intermediate image is an image generated with luminance set to belower than 100% on the basis of the specific image data when theluminances of the specific images SI1 and SI2 are set to 100%. That is,the plurality of intermediate images and the specific images SI1 and SI2are images generated on the basis of the same specific image data andonly having different luminances. Therefore, the plurality ofintermediate images are generated according to the number of luminances.For example, when luminances are set to 10%, 35%, 65%, and 100%, threeintermediate images and one specific image are generated on the basis ofthe specific image data.

FIG. 8 is an explanatory diagram showing an example of temporaltransition of the luminance of the backlights 221 and 222 in imagedisplay processing. In FIG. 8, with the abscissa set as a time axis, achange in luminance in a period TE (e.g., 3 seconds) from a state inwhich an image is displayed on the image display unit 20 until thespecific images SI1 and SI2 are displayed is shown. When the luminanceis changed on the basis of the same specific image data, after theplurality of intermediate images are displayed on the image display unit20, the specific images SI1 and SI2 are displayed.

As shown in FIG. 8, when the intermediate images MI1 and MI2 aredisplayed, the specific-image control unit 165 increases the luminanceof the backlights 221 and 222 such that an increase ratio of theluminance increases according to elapse of time. Therefore, whentemperature equal to or higher than the threshold is detected, ratherthan causing the user to visually recognize the specific images SI1 andSI2 at an instance of the detection, the specific-image control unit 165causes the user to visually recognize the specific images SI1 and SI2after causing the user to visually recognize the plurality ofintermediate images having different luminances. Consequently, thespecific-image control unit 165 causes the user to visually recognize asif the specific images SI1 and SI2 gradually emerge (hereinafterreferred to as “fade-in display” as well). The plurality of intermediateimages and each of the specific images SI1 and SI2 are equivalent to aplurality of kinds of first image light and a second image light in theappended claims.

When the plurality of intermediate images and the specific images SI1and SI2 are displayed on the image display unit 20 (step S21 in FIG. 4),the specific-image control unit 165 ends the specific image displayprocessing.

A-3. Specific Image Non-Display Processing

FIG. 9 is an explanatory diagram showing a flow of specific imagenon-display processing. In the specific image non-display processing, astate in which a specific image is detected according to a set detectioncondition and displayed on the image display unit 20 is changed to astate of non-display of the specific image when the specific image doesnot satisfy the detection condition or when a visual line direction ofthe user is changed.

In the specific image non-display processing, first, the specific-imagecontrol unit 165 determines whether the temperature of a region detectedas temperature equal to or higher than the threshold continues to be thetemperature equal to or higher than the threshold (step S31). When it isdetermined that the temperature of the region is the temperature equalto or higher than the threshold (step S31: YES), thevisual-line-direction determining unit 166 detects a change in thevisual line direction of the user (step S32). When a change in thevisual line direction of the user is not detected, that is, the visualline direction of the user remains fixed (step S32: NO), thespecific-image control unit 165 continues to monitor the temperature ofthe region detected as the temperature equal to or higher than thethreshold (step S31). The visual-line-direction determining unit 166monitors the visual line direction of the user (step S32).

When it is determined in the processing in step S31 that the temperatureof the region detected as the temperature equal to or higher than thethreshold (step S31: NO) and when a change in the visual line directionof the user is detected in the processing in step S32 (step S32: YES),after changing the specific images SI1 and SI2 displayed on the imagedisplay unit 20 to a plurality of intermediate images having differentluminances according to elapse of time, the specific-image control unit165 sets the luminance to 0% and sets the intermediate images tonon-display (step 33).

FIG. 10 is an explanatory diagram showing an example of temporaltransition of the luminance of the backlights 221 and 222 in the imagenon-display processing. In FIG. 10, with the abscissa set as a timeaxis, a change in luminance in the period TE from a state in which thespecific images SI1 and SI2 are displayed on the image display unit 20until the images are not displayed on the image display unit 20 isshown. When the specific-image control unit 165 changes images to bedisplayed on the image display unit 20 from the specific images SI1 andSI2 to a plurality of intermediate images having different luminances,the specific-image control unit 165 reduces the luminance such that adecrease ratio of the luminance increases according to elapse of time.Therefore, for example, when the temperature equal to or higher than thethreshold is not detected and when the visual line direction of the userchanges, the specific images SI1 and SI2 do not instantaneously cease tobe visually recognized by the user. The user visually recognizes as ifthe specific images SI1 and SI2 change to a plurality of intermediateimages having different luminances and gradually disappear (hereinaftersimply referred to as “fade-out display” as well).

When the specific images SI1 and SI2 and the plurality of intermediateimages are displayed on the image display unit 20 (step S33 in FIG. 9),the specific-image control unit 165 ends the specific image non-displayprocessing.

As explained above, in the head mounted display device 100 in thisembodiment, the operation unit 135 causes the image display unit 20 todisplay the specific images SI1 and SI2, which are generated on thebasis of the specific image data and change according to the elapse oftime, and the intermediate images MI1 and MI2. Therefore, in the headmounted display device 100 in this embodiment, since an image visuallyrecognized by the user gently changes according to the elapse of time,the burden on the visual sense of the user is reduced.

In the head mounted display device 100 in this embodiment, thespecific-image control unit 165 detects temperature equal to or higherthan the threshold and, then, after causing the image display unit 20 todisplay a plurality of intermediate images having different luminances,causes the image display unit 20 to display the specific images SI1 andSI2. The plurality of intermediate images are generated on the basis ofspecific image data created on the basis of a temperature distributionimage acquired by the thermography 62. The specific images SI1 and SI2are images generated on the basis of the specific image data anddifferent from the plurality of intermediate images. Therefore, the headmounted display device 100 in this embodiment causes the user tovisually recognize the specific images SI1 and SI2 after causing theuser to visually recognize the intermediate images according to theelapse of time rather than causing the user to suddenly visuallyrecognize the specific images SI1 and SI2 in a state in which only theoutside scene is visually recognized. Therefore, since changes of theoutside scene and the images visually recognized by the user are gentle,it is possible to further reduce the burden on the visual sense of theuser.

In the head mounted display device 100 in this embodiment, the pluralityof intermediate images and the specific images SI1 and SI2 are imagesdifferent only in luminance generated on the basis of the same specificimage data. The specific image control unit 165 adjusts the luminancesof the plurality of intermediate images and the specific images SI1 andSI2 to be different by adjusting a light amount of the backlights 221and 222. Therefore, in the head mounted display device 100 in thisembodiment, it is possible to generate the plurality of intermediateimages and the specific images SI1 and SI2 on the basis of one imagedata simply by controlling the luminances. Therefore, it is possible toreduce the burden on the visual sense of the user with simple control.

In the head mounted display device 100 in this embodiment, thespecific-image control unit 165 causes the image display unit 20 todisplay the plurality of intermediate images having different luminancesin the period TE (e.g., 3 seconds) set in advance and, when the periodTE ends, causes the image display unit 20 to display the specific imagesSI1 and SI2 having luminances respectively larger than the luminances ofthe plurality of intermediate images. When the specific-image controlunit 165 displays the intermediate images MI1 and MI2, thespecific-image control unit 165 increases the luminance of thebacklights 221 and 222 such that an increase ratio of the luminanceincrease according to elapse of time. In the period TE, thespecific-image control unit 165 changes the specific images SI1 and SI2displayed on the image display unit 20 to a plurality of intermediateimages having different luminances to display no image on the imagedisplay unit 20 after the end of the period TE. When the specific-imagecontrol unit 165 changes images to be displayed on the image displayunit 20 from the specific images SI1 and SI2 to the plurality ofintermediate images having different luminances, the specific-imagecontrol unit 165 reduces the luminances such that a decrease ratio ofthe luminances increases according to the elapse of time. Therefore, inthe head mounted display device 100 in this embodiment, it is possibleto cause the user to visually recognize as if the specific images SI1and SI2 gradually emerge through the plurality of intermediate images.Therefore, it is possible to further reduce the burden on the visualsense of the user.

In the head mounted display device 100 in this embodiment, thethermography 62 generates a temperature distribution image representinga distribution of temperature. The specific-image control unit 165creates specific image data according to the generated temperaturedistribution image. Therefore, in the head mounted display device 100 inthis embodiment, it is possible to cause the user to visually recognizean image involved in a temperature change of the outside scene.Therefore, convenience for the user is improved.

In the head mounted display device 100 in this embodiment, the 9-axissensor 66 detects a movement of the head of the user. Thevisual-line-direction determining unit 166 specifies a visual linedirection of the user according to the detected movement of the head.When the visual line direction of the user is fixed, the specific-imagecontrol unit 165 creates specific image data. Therefore, when the visualline direction of the user is not fixed, the head mounted display device100 in this embodiment does not cause the user to visually recognize theintermediate images and the specific images SI1 and SI2. Therefore, evenif the user changes the visual line direction, the transmitted outsidescene only changes. The user does not have to visually recognize agenerated image. Therefore, there is little change in the outside scenevisually recognized by the user. The burden on the visual sense of theuser is further reduced.

B. Second Embodiment

FIG. 11 is a block diagram functionally showing the configuration of ahead mounted display device 100 a in a second embodiment. The headmounted display device 100 a is different from the head mounted displaydevice 100 in the first embodiment in that a camera 61 is formed in animage display unit 20 a instead of the thermography 62 and a GPS module134, a radio communication unit 132, and an image determining unit 168are formed in a control unit 10 a. The other components are the same.

Like the thermography 62, the camera 61 is arranged in a positioncorresponding to the middle of the forehead of a user when the userwears the image display unit 20 a. The camera 61 picks up an image of anoutside scene, which is a scene on the outside of a visual linedirection of the user, and acquires an outside scene image. The camera61 is a monocular camera but may be a stereo camera. The camera 61 isequivalent to an image pickup unit in the appended claims.

The GPS module 134 receives a signal from a GPS satellite to therebyspecify the present position of the image display unit 20 a andgenerates information indicating the position. Since the presentposition of the image display unit 20 a is detected, the presentposition of the user of the head mounted display device 100 a isspecified. The GPS module 134 is equivalent to a position-informationacquiring unit in the appended claims.

The radio communication unit 132 transmits and receives various kinds ofinformation such as weather information and road traffic information toand from other apparatuses according to a predetermined radiocommunication standard such as a wireless LAN or Bluetooth. The imagedetermining unit 168 determines, through pattern matching, whether animage (e.g., an image of “sky”) same as a specific target imagerepresenting image data stored in advance in the storing unit 120 isincluded in the outside scene image. The image determining unit 168 isequivalent to a target extracting unit in the appended claims.

The specific-image control unit 165 in the second embodiment not onlyperforms detection of temperature but also performs detection of aspecific target image included in the outside scene image and performsvarious kinds of control on the basis of the present position and likeof the user and causes the image display unit 20 a to display a specificimage and a plurality of intermediate images. For example, thespecific-image control unit 165 specifies a region of the sky includedin the outside scene image. When the visual line direction of the useris fixed, the specific-image control unit 165 generates specific imagedata indicating the weather information received via the radiocommunication unit 132.

FIG. 12 is an explanatory diagram showing a flow of specific imagedisplay processing in the second embodiment. The specific image displayprocessing in the second embodiment is different from the specific imagedisplay processing in the first embodiment in a detection application tobe selected and a specific image and a plurality of intermediate imagesto be generated. Therefore, in the second embodiment, compared with thefirst embodiment, processing for generation and display of an advancenotice image in step S61 is added anew. Otherwise, the second embodimentis the same as the first embodiment. In explanation in the secondembodiment, an application of “weather information (FIG. 5)”(hereinafter referred to as “weather application” as well), which is adetection application, is selected. The advance notice image isequivalent to a plurality of kinds of first image light in the appendedclaims.

In the specific image display processing, when a detection condition ofthe weather application is set (step S45 in FIG. 12), the specific-imagecontrol unit 165 starts the camera 61, the 9-axis sensor 66, the radiocommunication unit 132, and the GPS module 134, which are devicesrelated to the weather application (step S46).

The image determining unit 168 determines as the detection conditionwhether a target image of “sky” is in a region equal to or larger than apredetermined region in the outside scene image (e.g., equal to orlarger than a half of the outside scene image) (step S47). When it isdetermined that the target image is not included in the outside sceneimage (step S47: NO), the image determining unit 168 continues tomonitor detection of the target image (step S47). When it is determinedthat the target image is included in the outside scene image (step S47:YES), the specific-image control unit 165 creates one advance noticeimage data in which an entire region where the target image is detectedon the basis of the specific image data is set as a region of acandidate representing a specific image. The specific-image control unit165 causes the image display unit 20 a to display a plurality of advancenotice images based on the one advance notice image data (step S61).

FIG. 13 is an explanatory diagram showing an example of an advancenotice image PI visually recognized by the user. As shown in FIG. 13,the advance notice image PI is displayed in the image display largestregion PN. The advance notice image PI is an image generated tocorrespond to the entire region determined as the target image of “sky”by the image determining unit 168 in the picked-up outside scene image.A plurality of advance notice images are generated on the basis of thesame advance notice image data by increasing the luminance of thebacklights 221 and 222 according to elapse of time.

After the advance notice image is displayed on the image display unit 20a (step S61 in FIG. 12), the visual-line-direction determining unit 166determines whether the visual line direction of the user is fixed (stepS48). When it is determined that the visual line direction of the useris not fixed (step S48: NO), the visual-line-direction determining unit166 continues to wait for the visual line direction of the user to befixed (step S48). When it is determined in the processing in step S48that the visual line direction of the user is fixed (step S48: YES), thespecific-image control unit 165 specifies a position where a specificimage is displayed in a region where the advance notice image isdisplayed (step S49).

FIG. 14 is an explanatory diagram showing an example of a specific imagevisually recognized by the user. In FIG. 14, a specific image SI3 and aspecific image SI4 displayed in the image display largest region PN isshown. The specific images SI3 and SI4 are images generated on the basisof the specific image data created by the specific image control unit165 on the basis of the information received from the radiocommunication unit 132. The specific-image control unit 165 displays thespecific image SI3 on the upper left and displays the specific image SI4on the upper right in the region where the advance notice image isdisplayed.

As explained above, in the head mounted display device 100 a in thesecond embodiment, the camera 61 picks up an image of the outside scene,which is a scene on the outside in the visual direction of the user, andacquires an outside scene image. The image determining unit 168determines, according to pattern matching, whether an image same as aspecific target image is included in the outside scene image. The GPSmodule 134 receives a signal from the GPS satellite to thereby specifythe present position of the user of the head mounted display device 100a. Therefore, in the head mounted display device 100 a in the secondembodiment, an image that the user is caused to visually recognize canbe controlled on the basis of detection of the specific target imageincluded in the outside scene image and position information of theuser. Therefore, convenience for the user is improved.

C. Third Embodiment

In a third embodiment, specific image display processing and specificimage changing processing for changing a specific image according to adetection condition are performed according to a detection applicationdifferent from the detection application in the embodiment explainedabove. In explanation in the third embodiment, a work supportapplication for performing work support for a user is selected as thedetection application.

FIG. 15 is an explanatory diagram showing the configuration of theexternal appearance of a head mounted display device 100 d in the thirdembodiment. As shown in FIG. 15, the head mounted display device 100 dis different from the head mounted display devices in the embodiments inthat a right eye image pickup camera 37 and a left eye image pickupcamera 38 are arranged in an image display unit 20 d. The head mounteddisplay device 100 d is the same as the head mounted display devices inthe embodiments in the other components. The right eye image pickupcamera 37 and the left eye image pickup camera 38 are small CCD camerasthat respectively pick up images of the right eye and the left eye ofthe user. In the following explanation, the right eye image pickupcamera 37 and the left eye image pickup camera 38 are collectivelyreferred to as eye image pickup cameras 37 and 38 as well. Images pickedup by the eye image pickup cameras 37 and 38 are referred to as eyepicked-up images.

FIG. 16 is a block diagram functionally showing the configuration of thehead mounted display device 100 d in the third embodiment. In the thirdembodiment, an image determining unit 168 d analyses images of the righteye and the left eye of the user in the eye picked-up image to specifythe size of the pupils of the right eye and the left eye. A specificmethod of specifying the size of the pupils is a method of applyingbinarization to pixels of picked-up image of the eyes on the basis ofpredetermined values of RGB, identifying pixels of the whites of theeyes and the irises of the eyes, and determining the size of the pupilsaccording to a ratio of the number of pixels identified as the irises ofthe eyes to the overall number of the pixels. The image determining unit168 d can specify a direction of view of the user with respect to thedirection of the head of the user based on the position of the pixel ofthe iris in the image of the eye. Therefore, a visual-line-directiondetermining unit 166 d can estimate a more detailed visual linedirection of the user by specifying the direction of view of the userwith respect to the direction of the head of the user in addition to thedirection of the image display unit 20 detected by the 9-axis sensor 66.The eye image pickup cameras 37 and 38 and the image determining unit168 d in the third embodiment are equivalent to a pupil specifying unitin the appended claims.

A specific-image control unit 165 d detects whether a specific targetstored in advance in the storing unit 120 is included in an outsidescene image and specifies the size of the specific target included inthe outside scene image to determine a distance between the user and thespecific target. If the determined distance is equal to or larger than athreshold, the specific-image control unit 165 d determines that thespecific target is included in the outside scene image. If thedetermined distance is smaller than the threshold, even if the specifictarget is included in the outside scene image, the specific-imagecontrol unit 165 d does not detect the specific target and determinesthat the specific target is not included in the outside scene image. Theimage determining unit 168 d can specify relative speed of movement ofthe specific target in the outside scene image by specifying positionsof the specific target in frames of the outside scene image. The camera61 and the specific-image control unit 165 d in the third embodiment areequivalent to a distance specifying unit in the appended claims.

FIGS. 17 and 18 are explanatory diagrams showing a flow of specificimage display processing in the third embodiment. The specific imagedisplay processing in the third embodiment is different from thespecific image display processing in the embodiments explained above inprocessing in step S76 and subsequent steps and is same as the specificimage display processing in the embodiments in processing up to stepS75. In the third embodiment, when a detection condition of the worksupport application is set (step S75), the specific-image control unit165 starts the camera 61, the 9-axis sensor 66, and the eye image pickupcameras 37 and 38, which are the devices related to the work supportapplication (step S76). Subsequently, as the detection condition, theimage determining unit 168 d determines whether a target image, which isan image of an electric drill serving as a specific target, is includedin an outside scene image (step S77). When it is determined that thetarget image is not included in the outside scene image (step S77: NO),the image determining unit 168 d continues to monitor detection of thetarget image (step S77). When it is determined that the target image isincluded in the outside scene image (step S77: YES), thevisual-line-direction determining unit 166 d determines whether thevisual line direction of the user is fixed (step S78). When it isdetermined that the visual line direction of the user is not fixed (stepS78: NO), the image determining unit 168 d determines that the targetimage is not detected and continues to monitor detection of the targetimage (step S77).

When it is determined in the processing in step S78 that the visual linedirection of the user is fixed (step S78: YES), the image determiningunit 168 d specifies the size of the pupils in an eye picked-up imageused in fade-in display control explained blow (step S79 in FIG. 18).Subsequently, the image determining unit 168 d specifies relative speedof movement of the target image with respect to the outside scene imageused for control of the fade-in display (step S80). The specific-imagecontrol unit 165 d sets, according to the size of the pupils and therelative speed of the movement of the target image, changing luminances,which are luminances changing according to elapse of time, ofintermediate images and a specific image in performing the fade-indisplay and a changing period, which is a period from the start ofdisplay of the intermediate images to display of the specific imageuntil completion of the fade-in display (step S81).

FIG. 19 is an explanatory diagram showing an example of temporaltransition of the luminance of the backlights 221 and 222 in imagedisplay processing. In FIG. 19, a curve C2 of a change in luminanceaccording to elapse of time in the fade-in display set on the basis ofthe size of the pupils and the relative speed of the movement of thetarget image and a curve C1 of a change in the luminance in the firstembodiment are shown. The specific-image control unit 165 d classifiesthe size of the pupils into two according to a predetermined threshold.When the luminance of the specific image is set to 100% in the casewhere the size of the pupils is smaller than the predeterminedthreshold, the specific-image control unit 165 d sets the luminance ofthe specific image to 70% when the size of the pupils is equal to orlarger than the predetermined threshold. In FIG. 19, the size of thepupils in the first embodiment is smaller than the predeterminedthreshold and the size of the pupils in the third embodiment is equal toor larger than the predetermined threshold. Therefore, in the thirdembodiment, when the fade-in display is started, the luminances of theintermediate images and the specific image are always smaller than theluminances in the first embodiment. The size of the pupils equal to orlarger than the predetermined threshold and the size of the pupilssmaller than the predetermined threshold are respectively equivalent toa first size and a second size in the appended claims.

Like the luminance of the specific image, the specific-image controlunit 165 d classifies the relative speed of the movement of the targetimage into two according to a predetermined threshold. As shown in FIG.19, when the relative speed of the movement of the target image is equalto or higher than the predetermined threshold, the specific-imagecontrol unit 165 d sets the changing period to the period TE as in thefirst embodiment. When the relative speed of the movement of the targetimage is lower than the predetermined threshold, the specific-imagecontrol unit 165 d sets the changing period to a period TE2 longer thanthe period TE as in the third embodiment. Therefore, in the thirdembodiment, on the curve C2 in the fade-in display, the changing periodfrom the start of display of the intermediate images until display ofthe specific image is the period TE2 and the luminance of the specificimage is 70% of the luminance in the first embodiment. The intermediateimages and the specific image are generated on the same image data.

When the changing luminance and the changing period in the fade-indisplay are set (step S81 in FIG. 18), as in the embodiments explainedabove, the specific-image control unit 165 d specifies a displayposition of the specific image based on the work support application,which is the detection application, (step S82) and performs theprocessing in steps S83 and S84 as in the embodiments.

FIG. 20 is an explanatory diagram showing an example of a specific imageSI10 visually recognized by the user. In FIG. 20, the visual field VR ofthe user who visually recognizes a target image OI1, which is an imageof the electric drill serving as the specific target, is shown. As shownin FIG. 20, the specific-image control unit 165 d displays the specificimage SI10 in a position not overlapping a main body section of theelectric drill other than a cord of the target image Oil in the outsidescene image. Identification of the target image OI1 is performedaccording to pattern matching as in the embodiments. The specific imageSI10 is an image based on image data set in the work support applicationand is a message image “please wear gloves and hold hands in front ofthe camera” for urging the user to wear gloves on both hands as worksupport for use of the electric drill.

In the work support application, when a specific condition is satisfiedafter the specific image SI10 (FIG. 20) is displayed, the specific-imagecontrol unit 165 d displays a specific image different from the specificimage SI10 according to the order of the work support. FIG. 21 is anexplanatory diagram showing a flow of specific image changingprocessing. The specific image changing processing is processing fordisplaying a specific image based on image data different from imagedata of the specific image SI10 when the specific condition is satisfiedin a state in which the specific image SI10 is displayed.

In the specific image changing processing, first, the specific imagecontrol unit 165 d determines whether the target image in the outsidescene image changes (step S91). When it is determined that the targetimage changes (step S91: YES), the specific-image control unit 165 ddetermines whether the change of the target image is a change conformingto the set order of the work support (step S92). When it is determinedthat the change of the target image is the change conforming to theorder of the work support (step S93), the specific-image control unit165 d determines whether a specific image set next in the order of thework support is present (step S93). When it is determined that thespecific image set next is present (step S93: YES), the specific-imagecontrol unit 165 d displays the specific image set next (step S95).

FIG. 22 is an explanatory diagram showing an example of a specific imageSI11 visually recognized by the user after the target image changes. InFIG. 22, as the target image set next according to the work order, anoutside scene image including a target image OI2 of the left hand and atarget image OI3 of the right hand of the user wearing the gloves inaddition to the target image OI1 is shown. In FIG. 22, the specificimage SI11 set to be displayed next to the specific image SI10 accordingto the work support is shown. The target images Oil, OI12, and OI3 aretarget images set according to the order of the work support. Therefore,the specific-image control unit 165 d displays the specific image SI11.The specific image SI11 is a message image “Checked! Please performwork” indicating that the user may perform work using the electricdrill. When the specific image SI11 set according to the order of thework support is displayed, the specific-image control unit 165 d endsthe specific image changing processing.

When the detected change of the target image is not a change conformingto a work instruction, for example, when the user holds the hands infront of the camera without wearing the gloves in the processing in stepS92 in FIG. 21 (step S92: NO), the specific-image control unit 165 ddisplays, as an advice message, a message image “Wrong! Please followthe instruction” for urging the user to follow the work support of thespecific image SI10 (FIG. 20) (step S99 in FIG. 21) and ends thespecific image changing processing.

When it is determined in the processing in step S91 that a change of thetarget image is not detected (step S91: NO), the specific-image controlunit 165 d determines whether the visual line direction of the userchanges and the target image OI1, which is a condition for displayingthe specific image SI10 (FIG. 20), is included in the outside sceneimage (step S94 in FIG. 21). When the visual line direction of the userdoes not greatly change and the target image OI1 is included in theoutside scene image (step S94: NO), the specific-image control unit 165d continues to monitor a change of the specific target (step S91).

When it is determined that the target image OI1 is not included in theoutside scene image (step S94: YES) or when it is determined in theprocessing in step S93 that a specific image set next according to thework support is absent (step S93: NO), the specific-image control unit165 d specifies changing speed of the visual line direction (step S96).As in the processing in steps S80 and S81 of the specific image displayprocessing shown in FIG. 18, the specific-image control unit 165 d sets,on the basis of the specified changing speed of the visual linedirection, a changing period for subjecting the displayed specific imageSI10 to fade-out display (step S97 in FIG. 21). Subsequently, thespecific-image control unit 165 d gradually reduces the luminance of thespecific image SI10 in the set changing period and sets an image basedon the image data of the specific image SI10 to non-display via theintermediate images.

As explained above, in the head mounted display device 100 d in thethird embodiment, the image determining unit 168 d analyzes the eyepicked-up images picked up by the eye image pickup cameras 37 and 38 tospecify the size of the pupils of the eyes of the user. When the size ofthe pupils is smaller than the predetermined threshold, thespecific-image control unit 165 d displays the intermediate images andthe specific image set to luminances lower than the luminances set whenthe size of the pupils is equal to or larger than the predeterminedthreshold. Therefore, in the head mounted display device 100 d in thethird embodiment, when the size of the pupils of the eyes of the user islarge, that is, when brightness around the user is low, control forreducing the luminances of the intermediate images and the specificimage is performed. When the brightness around the user is high, controlfor increasing the luminances of the intermediate images and thespecific image is performed. Therefore, the luminances of theintermediate images and the specific image are controlled according tothe brightness around the user. Consequently, it is possible to reducethe visual burden on the user without causing the user to visuallyrecognize an image at luminance higher than necessary. Further, it ispossible to cause the user to visually recognize an image havingbrightness enough for enabling the user to visually recognize the image.

In the head mounted display device 100 d in the third embodiment, theimage determining unit 168 d specifies positions of the specific targetin the frames of the outside scene image to specify relative speed ofmovement of the specific target in the outside scene image. Thespecific-image control unit 165 d sets the changing period long when therelative speed of the movement of the target image is equal to or higherthan the predetermined threshold and sets the changing period short whenthe relative speed of the movement of the target image is lower than thepredetermined threshold. Therefore, in the head mounted display device100 d in the third embodiment, when the relative speed of the movementof the target image is high, time until completion of the fade-indisplay is set long. Therefore, it is possible to reduce the visualburden on the user by reducing a visual change for the user.

In the head mounted display device 100 d in the third embodiment, thespecific-image control unit 165 d specifies the size of the specifictarget included in the outside scene image to determine a distancebetween the user and the specific target. If the determined distance isequal to or larger than a threshold, the specific-image control unit 165d determines that the specific target is included in the outside sceneimage. If the determined distance is smaller than the threshold, even ifthe specific target is included in the outside scene image, thespecific-image control unit 165 d does not detect the specific targetand determines that the specific target is not included in the outsidescene image. When the target image, which is the image of the specifictarget, is included in the outside scene image, the specific-imagecontrol unit 165 d performs the fade-in display of the intermediateimages and the specific image. Therefore, in the head mounted displaydevice 100 d in the third embodiment, an image of the specific target ispicked up and, in addition, only when the distance between the user andthe specific target is equal to or smaller than a fixed distance, theintermediate images and the specific image are displayed. Therefore,when the specific target is not present in a position close to the user,the specific image and the like, which are information unnecessary forthe user, is not displayed. Therefore, convenience for the user isimproved.

In the head mounted display device 100 d in the third embodiment, theimage data, on which the specific image SI10 is based, is the messagefor urging the user of the work support application to follow the orderof the work. Therefore, the user can perform work, which the user shouldperform, safely and in a correct procedure. Convenience for the user isimproved.

D. Modifications

The invention is not limited to the embodiments explained above. Theinvention can be carried out in various forms without departing from thespirit of the invention. For example, modifications explained below arealso possible.

D1. Modification 1

In the embodiments, the fade-in display and the fade-out display areexplained using the heat detection application and the weatherapplication as the examples of the selected application. However, thedetection application, the specific image, and the intermediate imagescan be variously modified.

FIGS. 23 and 24 are explanatory diagrams showing examples ofintermediate images visually recognized by the user. In FIGS. 23 and 24,modifications of the intermediate images MI1 and MI2 (FIG. 7) in thefirst embodiment are shown. In FIGS. 23 and 24, intermediate imagesMI1a, MI2a, MI1b, and MI2b included in regions of the specific imagesSI1 and SI2 finally displayed on the image display unit 20 by thefade-in display are shown. In this modification, in the fade-in display,unlike the first embodiment, luminances are not gradually changed. Aftera plurality of intermediate images generated on the basis of differentimage data are displayed, the specific images SI1 and SI3 are displayed.The specific-image control unit 165 creates a plurality of intermediateimage data indicating a part of specific image data and causes the userto visually recognize the intermediate image MI1a (FIG. 23), theintermediate image MI1b (FIG. 24), and the specific image SI1 (FIG. 6),which are generated on the basis of the intermediate image data, in thisorder. Therefore, in this modification, the user is not caused tosuddenly visually recognize the specific images SI1 and SI2 in a statein which only an outside view is visually recognized. A region of animage that the user is caused to visually recognize is increasedaccording to elapse of time. Therefore, since changes in the outsidescene and the image visually recognized by the use are gentle, theburden on the visual sense of the user is reduced. The fade-in displaymay be performed according to a combination of a change in luminance anda change in a display region.

FIG. 25 is an explanatory diagram showing an example of an intermediateimage MI1c visually recognized by the user. FIG. 26 is an explanatorydiagram showing an example of specific images SI1c, SI2c, and SI5cvisually recognized by the user. In this modification, as in the firstembodiment, the fade-in display is performed by gradually increasingluminances. At the same time, an image display region is reduced fromthe intermediate image MI1c to the specific image SI1c. In this way, theintermediate image may be a region larger than the specific image.

D2. Modification 2

FIG. 27 is an explanatory diagram showing an example of specific imagesSI6, SI7, and SI8 visually recognized by the user. In FIG. 27, thevisual field VR visually recognized by the user when “route guidance” isselected as the detection application is shown. In this modification,the GPS module 134 specifies the present position of the user. When thespecified position is an intersection, the specific-image control unit165 causes the image display unit 20 to display the specific images SI6,SI7, and SI8 in the route guidance.

FIG. 28 is an explanatory diagram showing an example of a menu imageIMG2 including specific images visually recognized by the user. In FIG.28, the visual fields VR visually recognized by the user when “standbymenu display” is selected as the detection application is shown. In thismodification, when the GPS module 134 specifies the present position ofthe user and the user does not move from the specified present positionfor a fixed time, the specific-image control unit 165 causes the imagedisplay unit 20 to display a menu screen for “music start” and the like.

FIG. 29 is an explanatory diagram showing an example of specific imagesSI9 and SI10 visually recognized by the user. In FIG. 29, the visualfield VR visually recognized by the user when “standby screen display”is selected as the detection application is shown. In this modification,the image determining unit 168 recognizes “sky”, which is a specifictarget image, in an outside scene image. At the same time, the GPSmodule 134 specifies the present position of the user. When the userdoes not move from the specified present position for a fixed time, thespecific-image control unit 165 causes the image display unit 20 todisplay the specific images SI9 and SI10.

D3. Modification 3

In the first embodiment, in the fade-in display and the fade-outdisplay, the period TE for changing luminances in displaying theintermediate images MI1 and MI2 is the same. However, the period TE maybe different. For example, in the fade-in display, the period TE may belong compared with the fade-out display. In the first embodiment, whenthe intermediate images MI1 and MI2 are displayed, an increase ratio ofluminances is controlled to be large according to elapse of time.However, the increase ratio of luminances is not limited to this and canbe variously changed. For example, the increase ratio of luminances maybe fixed with respect to the elapse of time or may change stepwise withrespect to the elapse of time.

In the embodiment, as shown in FIGS. 8 and 10, the specific-imagecontrol unit 165 increases and reduces the luminances between 0% and100%. However, an upper limit value and a lower limit value of theluminances are not limited to this and can be variously modified. Forexample, the specific-image control unit 165 may increase and reduce theluminances between 20% and 90%.

In the first embodiment, the fade-in display and the fade-out displayare performed. However, a method of displaying the intermediate imagesMI1 and MI2 and the specific images SI1 and SI2 is not limited to thisand can be variously modified. For example, it is also possible that,while the images are blinked at certain two luminances, in the imagedisplay largest region PN, the regions of the intermediate imagesgradually increase and change to the regions of the specific images. Itis also possible that the fade-in display and the fade-out display areperformed by increasing and reducing the luminances while blinking theimages.

In the embodiment, one specific image is finally displayed on the basisof the detection condition. However, the specific image can be variouslymodified. For example, a plurality of specific images may be identifiedand displayed on the basis of the detection condition. In the firstembodiment, a color of the specific image may be different not onlyaccording to the determination whether detected temperature is equal toor higher than the threshold but also according to the detectedtemperature is equal to or higher than which of a plurality of setthreshold temperatures. When the detected temperature is hightemperature, a specific image having a larger R component among RGBcomponents may be displayed. It is possible to attract the attention ofthe user concerning a region having higher temperature by forming anouter frame of the displayed specific image as a jagged shape ratherthan a circle.

In the embodiment, the selection menu screen IMG1 (FIG. 5) of thedetection application is explained as an example. However, the selectionmenu screen IMG1 of the detection application is not limited to this andcan be variously changed. For example, an end button for ending anapplication may be included in the selection menu screen IMG1. Selectionbuttons for content reproduction and the like different from theselection buttons of the detection application may be included.

D4. Modification 4

In the third embodiment, the changing period until the completion of thedisplay of the specific image in the fade-in display is set according tothe relative speed of the movement of the target image in the outsidescene image. However, a method of setting the changing period is notlimited to this and can be variously modified. For example, the changingperiod may be set according to the specified size of the pupils of theuser. The specific-image control unit 165 d sets the changing periodlonger as the specified size of the pupils of the eyes of the user islarger. In this modification, when the size of the pupils of the eyes ofthe user is large, that is, when the brightness around the user is low,the changing period until the completion of the fade-in display is setto be long. Therefore, when the user is caused to visually recognize theintermediate images and the specific image, it is possible to preventthe visual burden on the user from increasing.

In the third embodiment, the changing period until the completion of thefade-in display is set according to the comparison of the relative speedof the movement of the target image and the predetermined threshold.However, control other than the setting of the changing period may beperformed according to the relative speed of the movement of the targetimage. For example, when the relative speed of the movement of thetarget image is equal to or higher than the threshold, as in the secondembodiment, intermediate images based on image data different from theimage data, on which the specific image is based, may be displayed. Theintermediate images in this modification may be, for example, only animage other than the message in the specific image SI10 (FIG. 20). Theimage other than the message in the specific image SI10 in thismodification is equivalent to a pre-display image in the appendedclaims. In this modification, even when the target image is included inthe outside scene image, when the relative speed of the movement of thetarget image is large, the intermediate images are displayed in apreparation stage before the specific image is displayed. Consequently,it is possible to reduce a change in the outside scene visuallyrecognized by the user and reduce the visual burden on the user.

In the third embodiment, the changing period in the fade-in display isset according to the relative speed of the movement of the target imageincluded in the outside scene image. However, the setting of thechanging period is not limited to this and can be variously modified.For example, the 9-axis sensor 66 of the image display unit 20 mayspecify the speed of the movement of the user by estimating a movementof the entire body of the user in addition to the movement of the headof the user. When the speed of the movement of the user is high, in somecase, a change per short time of the visual field VR visually recognizedby the user is large. Therefore, in this modification, when the speed ofthe movement of the user is high, the specific-image control unit 165 dsets the changing period in the fade-in display long. Consequently, whenthe movement of the user is fast, a ratio of a change of theintermediate images visually recognized by the user decreases.Therefore, it is possible to reduce the visual burden on the user.

When the speed of the movement of the user or the relative speed of themovement of the target image included in the outside scene image ishigh, it is possible to attract some attention of the user by outputtingsound via the earphones 32 and 34 in addition to increasing the changingperiod in the fade-in display. When the speed of the movement of theuser or the relative speed of the movement of the target image is high,in some case, it is difficult to cause the user to visually recognizethe specific image. In that case, in this modification, a specific imagescheduled to be displayed is notified to the user by the sound output.Therefore, convenience for the user is improved.

The specific-image control unit 165 d may set, on the basis of contentof the specific image, the relative speed of the movement of the targetimage included in the outside scene image, the speed of the movement ofthe user, and the like, positions where the intermediate images and thespecific image are displayed. For example, when the specific image is amessage image for attract emergency attention of the user, thespecific-image control unit 165 d displays the specific image in thecenter of the image display largest region PN and sets the changingperiod of the fade-in display short. Consequently, the user can quicklyvisually recognize the specific image. Convenience for the user isfurther improved. Even if the specific image attracts emergencyattention of the user, for example, when the image is already displayedwithin 5 minutes, the specific-image control unit 165 d displays thespecific image in a position other than the center of the image displaylargest region PN to change the display position of already-informedcontent and cause the user to visually recognize a wider outside scene.Consequently, convenience for the user is further improved.

In the embodiment, when the visual direction of the user is fixed, theposition where the specific image is displayed is specified. However,when the visual direction of the user changes in a predetermined rangewithout being fixed, the visual line direction may be assumed to befixed. For example, even when the visual line direction of the userfluctuates in a range of a threshold set in advance, it is determinedthat the visual line direction is fixed. Consequently, the intermediateimages and the specific image are easily displayed. Convenience for theuser is improved.

In the third embodiment, the setting of the luminances and the settingof the changing period in the fade-in display are performed. However,the setting of the luminances and the setting of the changing period maybe used not only in the fade-in display but also in the fade-outdisplay. When the setting of the luminances and the setting of thechanging period are used in the fade-out display, for example, even whenthe target image is not included in the outside scene image, thespecific image does not instantaneously change to non-display. Thespecific image gradually changes to non-display through the intermediateimages. Therefore, it is possible to reduce the visual burden on theuser.

In the specific image changing processing in the third embodiment, whenthe specific image SI11 (FIG. 22) set next to the specific image SI10(FIG. 20) according to the order of the work support is present, thefade-in display and the fade-out display are not performed and thespecific image SI11 is displayed. However, the fade-in display and thefade-out display may be performed when the specific image is changed.For example, in the specific image changing processing in the thirdembodiment, the specific image SI11 may be subjected to the fade-indisplay after the specific image SI10 is subjected to the fade-outdisplay. It is also possible that positions where the specific imageSI10 and the specific image SI11 are displayed are different on theimage display largest region PN and the fade-out display of the specificimage SI10 and the fade-in display of the specific image SI11 aresimultaneously performed or the fade-out display or the fade-in displaymay be applied to only one of the specific images.

In the third embodiment, the size of the pupils of the eyes of the useris specified by the binarization of the eye picked-up images picked upby the eye image pickup cameras 37 and 38. However, a method ofspecifying the size of the pupils is not limited to this and can bevariously modified. For example, an emitting section and a receivingsection for an infrared ray formed in the image display unit 20 d mayspecify the size of the pupils. In this modification, the emittingsection for the infrared ray emits the infrared ray to the eyes of theuser and the receiving section for the infrared ray receives reflectedlight. The whites of the eyes and the irises of the eyes have differentreflectances of the infrared ray. Therefore, the size of the pupils canbe specified using the reflected light received by the light receivingsection.

The changing period and the luminances in the fade-in display and thefade-out display may be individually set by operating the operation unit135. A predetermined changing period and predetermined luminances may beset according to a set age.

In the embodiment, the specific-image control unit 165 adjusts the lightamount of the backlights 221 and 222 to thereby adjust the luminances ofthe plurality of intermediate images and the specific image to bedifferent. However, a method of changing the luminances is not limitedto this and can be variously modified. For example, the backlightcontrol unit 201, the right LCD control unit 211, the right backlight221, and the right LCD 241 equivalent to the image-light generating unitin the embodiment may be configured by an organic EL(Electro-Luminescence) display and an organic EL control unit. In thismodification, the luminances change when a light amount of emitted lightof the display itself is controlled without using the backlights 221 and222. The organic El display and the organic EL control unit in thismodification are equivalent to an image modulating element in theappended claims.

D5. Modification 5

In the embodiments, the operation unit 135 is formed in the control unit10. However, a form of the operation unit 135 can be variously modified.For example, a user interface functioning as the operation unit 135 maybe provided separately from the control unit 10. In this case, since theoperation unit 135 is separate from the control unit 10 on which thepower supply 130 and the like are formed, the operation unit 135 can bereduced in size and operability for the user is improved. When a 9-axissensor for detecting movement of the operation unit 135 is formed in theoperation unit 135 and various kinds of operation are performed on thebasis of the detected movement, the user can sensuously operate the headmounted display device 100.

For example, the image-light generating unit may include an organic ELdisplay and an organic EL control unit. For example, in the image-lightgenerating unit, LCOS (Liquid crystal on silicon; LCOS is a registeredtrademark), a digital micro mirror device, or the like can be usedinstead of the LCD. For example, the invention can also be applied to ahead mounted display of a laser retinal projection type. In the case ofthe laser retinal projection type, a “region where image light can beemitted in the image-light generating unit” can be defined as an imageregion recognized by the eyes of the user.

For example, the head mounted display may be a head mounted display inwhich the optical-image display unit covers only a part of the eyes ofthe user, in other words, the optical-image display unit does notcompletely cover the eyes of the user. The head mounted display may be ahead mounted display of a so-called monocular type.

FIGS. 30A and 30B are explanatory diagrams showing the externalconfiguration of the head mounted display device 100 b in themodification. In an example shown in FIG. 30A, a head mounted displaydevice 100 b in the modification is different from the head mounteddisplay device 100 shown in FIG. 1 in that an image display unit 20 bincludes a right optical-image display unit 26 b instead of the rightoptical-image display unit 26 and includes a left optical-image displayunit 28 b instead of the left optical-image display unit 28. The rightoptical-image display unit 26 b is formed smaller than the opticalmember in the embodiments and is arranged obliquely above the right eyeof the user during mounting of the head mounted display device 100 b.Similarly, the left optical-image display unit 28 b is formed smallerthan the optical member in the embodiments and is arranged obliquelyabove the left eye of the user during mounting of the head mounteddisplay device 100 b. In an example shown in FIG. 30B, the head mounteddisplay device 100 b in the modification is different from the headmounted display device 100 shown in FIG. 1 in that an image display unit20 c includes a right optical-image display unit 26 c instead of theright optical image display 26 and includes a left optical-image displayunit 28 c instead of the left optical-image display unit 28. The rightoptical-image display unit 26 c is formed smaller than the opticalmember in the embodiments and is arranged obliquely below the right eyeof the user during mounting of the head mounted display. The leftoptical-image display unit 28 c is formed smaller than the opticalmember in the embodiments and is arranged obliquely below the left eyeof the user during mounting of the head mounted display. In this way,the optical-image display unit only has to be arranged near the eyes ofthe user. The size of the optical members formed in the optical-imagedisplay unit is also arbitrary. The head mounted display device 100 canbe realized in which the optical-image display unit covers only a partof the eyes of the user, in other words, the optical-image display unitdoes not completely cover the eyes of the user.

As the earphones, an ear hook type or a headband type may be adopted.The earphones may be omitted. For example, the image display unit may beconfigured as a head mounted display mounted on vehicles such as anautomobile and an airplane. For example, the image display unit may beconfigured as a head mounted display incorporated in body protectiveequipment such as a helmet.

The configuration of the head mounted display device 100 in theembodiments is only an example and can be variously modified. Forexample, one of the direction key 16 and the track pad 14 provided inthe control unit 10 may be omitted. Another operation interface such asan operation stick may be provided in addition to or instead of thedirection key 16 and the track pad 14. Input devices such as a keyboardand a mouse can be connected to the control unit 10. The control unit 10may receive inputs from the keyboard and the mouse.

As the image display unit, for example, an image display unit of anothershape such as an image display unit worn like a cap may be adoptedinstead of the image display unit 20 worn like eyeglasses. The earphones32 and 34 can be omitted as appropriate.

In the embodiments, the head mounted display device 100 may guide imagelight representing the same image to the left and right eyes of the userand cause the user to visually recognize a two-dimensional image or mayguide image light representing different images to the left and righteyes of the user and cause the user to visually recognize athree-dimensional image.

In the embodiments, apart of the components realized by hardware may bereplaced with software. Conversely, apart of the components realized bysoftware may be replaced with hardware. For example, in the embodiments,the image processing unit 160 and the sound processing unit 170 arerealized by the CPU 140 reading out and executing a computer program.However, these functional units may be realized by a hardware circuit.

When a part or all of the functions of the invention are realized bysoftware, the software (a computer program) can be provided while beingstored in a computer-readable recording medium. In the invention, the“computer-readable recording medium” is not limited to portablerecording media such as a flexible disk and a CD-ROM and includesvarious internal storage devices in the computer such as a RAM and a ROMand external storage devices fixed to the computer such as a hard disk.

In the embodiments, as shown in FIGS. 1 and 2, the control unit 10 andthe image display unit 20 are formed as separate components. However,the configuration of the control unit 10 and the image display unit 20is not limited to this and can be variously modified. For example, allthe components formed in the control unit 10 may be formed on the insideof the image display unit 20 or apart of the components may be formed.The power supply 130 in the embodiment may be independently formed andcan be replaced. The components formed in the control unit 10 may beredundantly formed in the image forming unit 20. For example, the CPU140 shown in FIG. 2 may be formed in both of the control unit 10 and theimage display unit 20. Functions performed by the CPU 140 formed in thecontrol unit 10 and a CPU formed in the image display unit 20 may beseparated.

In the embodiments, the specific-image control unit 165 creates specificimage data and transmits a control signal for the specific image data tothe image processing unit 160 and the display control unit 190 tocontrol the intermediate images and the like. However, thespecific-image control unit 165 does not always need to control theintermediate images and the like. The entity of the control can bevariously changed. For example, instead of the specific-image controlunit 165, the image processing unit 160 and the display control unit 190may create the specific image data. The backlight control units 201 and202 of the image display unit 20 may adjust luminance to change imagelight generated on the basis of the specific image data.

The control unit 10 and the image display unit 20 may be integrated toconfigure a wearable computer attached to clothes of the user.

The invention is not limited to the embodiments and the modificationsexplained above and can be realized in various configurations withoutdeparting from the spirit of the invention. For example, the technicalfeatures in the embodiments and the modifications corresponding to thetechnical features in the aspects described in the summary can bereplaced or combined as appropriate in order to solve apart or all ofthe problems or in order to attain a part or all of the effects. Unlessthe technical features are explained in this specification as essentialtechnical features, the technical features can be deleted asappropriate.

The entire disclosure of Japanese Patent Application Nos. 2013-145642,filed Jul. 11, 2013 and 2014-053189, filed Mar. 17, 2014 are expresslyincorporated by reference herein.

What is claimed is:
 1. A transmission type head mounted display devicecomprising: an image display unit including an image-light generatingunit configured to generate image light on the basis of image data andemit the image light, the image display unit allowing a user to visuallyrecognize the image light as a virtual image and transmitting an outsidescene in a state in which the image display unit is worn on a head ofthe user; and a control unit configured to set, as the image light thatthe control unit allows the user to visually recognize using the imagedisplay unit, specific image light generated on the basis of setspecific image data and changing according to elapse of time, whereinthe specific image data is set on the basis of specific information andincludes a plurality of kinds of first image light and second imagelight different from the plurality of kinds of first image light, thecontrol unit changes the image light, which the control unit allows theuser to visually recognize using the image display unit, from theplurality of kinds of first image light to the second image lightaccording to the elapse of time by performing at least one of an imagelight luminance adjustment and an image light size adjustment, in theimage light luminance adjustment: each of the plurality of kinds offirst image light and the second image light have different luminancesand luminance of the second image light is larger than luminances ofeach of the plurality of kinds of first image light, the control unitallows, using the image display unit, when the control unit changes afirst state in which the control unit does not allow the user tovisually recognize the plurality of kinds of first image light or thesecond image light to a second state in which the control unit allowsthe user to visually recognize the second image light after allowing theuser to visually recognize the plurality of kinds of first image light,the user to visually recognize the plurality of kinds of first imagelight such that the luminance of the plurality of kinds of first imagelight increases according to the elapse of time, and the control unitallows, when the control unit changes the second state to the firststate, the user to visually recognize the plurality of kinds of firstimage light such that the luminance decreases according to the elapse oftime, and in the image light size adjustment: each of the plurality ofkinds of first image light is a part of the second image light, thecontrol unit allows, using the image display unit, when the control unitchanges the first state to the second state, the user to visuallyrecognize the plurality of kinds of first image light such that a sizeof the plurality of kinds of first image light increases according tothe elapse of time, and the control unit allows, when the control unitchanges the second state to the first state, the user to visuallyrecognize the plurality of kinds of first image light such that the sizeof the plurality of kinds of image light decreases according to theelapse of time.
 2. The head mounted display device according to claim 1,wherein the image-light generating unit is configured by an imagemodulation element capable of adjusting an amount of light to beemitted, and in the image light luminance adjustment, the control unitadjusts the luminances of each of the plurality of kinds of first imagelight and the second image light to be different by adjusting the amountof light emitted from the image modulation element.
 3. The head mounteddisplay device according to claim 2, wherein the image-light generatingunit includes, as the image modulation element, a light source capableof adjusting an amount of light to be emitted and an image formationpanel configured to convert the light emitted from the light source intothe image light, and the control unit adjusts the luminances of each ofthe plurality of kinds of first image light and the second image lightto be different by adjusting the amount of the light emitted from thelight source.
 4. The head mounted display device according to claim 1,wherein in the image light luminance adjustment: the control unitallows, using the image display unit, when the control unit changes thefirst state to the second state, the user to visually recognize theplurality of kinds of first image light such that an increase ratio ofthe luminance of the plurality of kinds of first image light increasesaccording to the elapse of time, and the control unit allows, when thecontrol unit changes the second state to the first state, the user tovisually recognize the plurality of kinds of first image light such thata decrease ratio of the luminance increases according to the elapse oftime.
 5. The head mounted display device according to claim 1, furthercomprising a pupil specifying unit configured to specify a size ofpupils of the user, wherein, in the image light luminance adjustment,the control unit sets luminances of each of the plurality of kinds offirst image light and the second image light such that luminance at atime when the specified size of the pupils is a second size larger thana first size is smaller than luminance at a time when the specified sizeof the pupils is the first size.
 6. The head mounted display deviceaccording to claim 1, further comprising a pupil specifying unitconfigured to specify a size of pupils of the user, wherein the controlunit sets time for changing the plurality of kinds of first image lightto the second image light longer as the specified size of the pupils islarger when the control unit changes a state in which the specific imagelight is not allowed to be visually recognized by the user to a state inwhich the specific image light is allowed to be visually recognized bythe user.
 7. The head mounted display device according to claim 1,further comprising a temperature detecting unit configured to detect atemperature distribution of the outside scene in a visual line directionof the user, wherein the specific information includes information forspecifying the detected temperature distribution of the outside scene.8. The head mounted display device according to claim 1, furthercomprising: an image pickup unit configured to pick up an image of theoutside scene in a visual line direction of the user; and a targetextracting unit configured to extract a specific target included in thepicked-up image, wherein the specific information is informationconcerning the extracted specific target.
 9. The head mounted displaydevice according to claim 8, wherein the target extracting unitspecifies speed of a movement of the specific target in an image pickuprange of the image pickup unit, and the control unit sets time forchanging the plurality of kinds of first image light to the second imagelight longer as the specified speed of the movement of the specifictarget is higher.
 10. The head mounted display device according to claim8, wherein the target extracting unit specifies speed of a movement ofthe specific target in an image pickup range of the image pickup unit,and when the specified speed of the specific target is equal to orhigher than a set first threshold, the control unit sets, as the imagelight that the control unit allows the user to visually recognize usingthe image display unit, pre-display image light generated on the basisof image data different from the specific image light before setting thespecific image light.
 11. The head mounted display device according toclaim 8, further comprising a distance specifying unit configured tospecify a distance between the specific target and the image displayunit, wherein the control unit sets the specific image light when thespecified distance is equal to or smaller than a set second threshold.12. The head mounted display device according to claim 11, wherein thespecific information is information concerning an operation that theuser should perform for the specific target.
 13. The head mounteddisplay device according to claim 8, wherein the target extracting unitspecifies a speed of a movement of the specific target in an imagepickup range of the image pickup unit, in the image light luminanceadjustment, the control unit sets luminance of the plurality of kinds offirst image light based on the specified speed of the movement of thespecific target, and in the image light size adjustment, the controlunit sets a size of the plurality of kinds of first image light based onthe specified speed of the movement of the specific target.
 14. The headmounted display device according to claim 1, further comprising aposition-information acquiring unit configured to acquire positioninformation for specifying a position of the user, wherein the specificinformation includes the acquired position information.
 15. The headmounted display device according to claim 1, further comprising avisual-line-direction specifying unit configured to acquire visual linedirection information, which is information for specifying a visual linedirection of the user, wherein the specific information includes thevisual line direction information.
 16. The head mounted display deviceaccording to claim 1, further comprising a movement specifying unitconfigured to specify speed of a movement of the user, wherein thecontrol unit sets time for changing the plurality of kinds of firstimage light to the second image light longer as the specified speed ofthe movement of the specific target is higher.
 17. The head mounteddisplay device according to claim 1, further comprising a pupilspecifying unit configured to specify a size of pupils of the user,wherein in the image light size adjustment the control unit sets a sizeof each of the plurality of kinds of first image light and the secondimage light based on the specified size of the pupils of the user. 18.The head mounted display device according to claim 1, further comprisinga movement specifying unit configured to specify a speed of a movementof the user, in the image light luminance adjustment, the control unitsets luminance of the plurality of kinds of first image light based onthe specified speed of the movement of the user, and in the image lightsize adjustment, the control unit sets a size of the plurality of kindsof first image light based on the specified speed of the movement of theuser.
 19. A control method for a transmission type head mounted displaydevice including an image display unit including an image-lightgenerating unit configured to generate image light on the basis of imagedata and emit the image light, the image display unit allowing a user tovisually recognize the image light as a virtual image and transmittingan outside scene in a state in which the image display unit is worn on ahead of the user, the control method comprising setting, on the basis ofspecific information and as the image light that the user is allowed tovisually recognize using the image display unit, specific image lightgenerated on the basis of set specific image data and changing accordingto elapse of time, the specific image light including a plurality ofkinds of first image light and second image light different from theplurality of kinds of first image light, changing the image light thatthe user is allowed to visually recognize using the image display unitfrom the plurality of kinds of first image light to the second imagelight according to the elapse of time by performing at least one of animage light luminance adjustment and an image light size adjustment,wherein in the image light luminance adjustment: each of the pluralityof kinds of first image light and the second image light have differentluminances and luminance of the second image light is larger thanluminances of each of the plurality of kinds of first image light, whena first state in which the user is not allowed to visually recognize theplurality of kinds of first image light or the second image lightchanges to a second state in which the user is allowed to visuallyrecognize the second image light after the user is allowed to visuallyrecognize the plurality of kinds of first image light, the user isallowed to visually recognize the plurality of kinds of first imagelight such that the luminance of the plurality of kinds of first imagelight increases according to the elapse of time, and when the secondstate changes to the first state, the user is allowed to visuallyrecognize the plurality of kinds of first image light such that theluminance decreases according to the elapse of time, and in the imagelight size adjustment: each of the plurality of kinds of first imagelight is a part of the second image light, when the first state changesto the second state, the user is allowed to visually recognize theplurality of kinds of first image light such that a size of theplurality of kinds of first image light increases according to theelapse of time, and when the second state changes to the first state,the user is allowed to visually recognize the plurality of kinds offirst image light such that the size of the plurality of kinds of imagelight decreases according to the elapse of time.
 20. A transmission typehead mounted display device comprising: an image display unit includingan image-light generating unit configured to generate image light on thebasis of image data and emit the image light, the image display unitallowing a user to visually recognize the image light as a virtual imageand transmitting an outside scene in a state in which the image displayunit is worn on a head of the user; a control unit configured to set, asthe image light that the control unit allows the user to visuallyrecognize using the image display unit, specific image light generatedon the basis of set specific image data and changing according to elapseof time; and a pupil specifying unit configured to specify a size ofpupils of the user, wherein the specific image data is set on the basisof specific information, the specific image light includes a pluralityof kinds of first image light and second image light different from theplurality of kinds of first image light, the control unit changes theimage light, which the control unit allows the user to visuallyrecognize using the image display unit, from the plurality of kinds offirst image light to the second image light according to the elapse oftime, each of the plurality of kinds of first image light and the secondimage light have different luminances, and the control unit performs atleast one of sets luminances of each of the plurality of kinds of firstimage light and the second image light such that luminance at time whenthe specified size of the pupils is a second size larger than a firstsize is smaller than luminance at time when the specified size of thepupils is the first size, and sets time for changing the plurality ofkinds of first image light to the second image light longer as thespecified size of the pupils is larger when the control unit changes astate in which the specific image light is allowed to be visuallyrecognized by the user to a state in which the specific image light isallowed to be visually recognized by the user.
 21. A transmission typehead mounted display device comprising: an image display unit includingan image-light generating unit configured to generate image light on thebasis of image data and emit the image light, the image display unitallowing a user to visually recognize the image light as a virtual imageand transmitting an outside scene in a state in which the image displayunit is worn on a head of the user; a control unit configured to set, asthe image light that the control unit allows the user to visuallyrecognize using the image display unit, specific image light generatedon the basis of set specific image data and changing according to elapseof time; an image pickup unit configured to pick up an image of theoutside scene in a visual line direction of the user; and a targetextracting unit configured to extract a specific target included in thepicked-up image, wherein the specific image data is set on the basis ofspecific information, the specific information is information concerningthe extracted specific target, the specific image light includes aplurality of kinds of first image light and second image light differentfrom the plurality of kinds of first image light, and the control unitchanges the image light, which the control unit allows the user tovisually recognize using the image display unit, from the plurality ofkinds of first image light to the second image light according to theelapse of time, the target extracting unit specifies speed of a movementof the specific target in an image pickup range of the image pickupunit, and the control unit performs at least one of sets time forchanging the plurality of kinds of first image light to the second imagelight longer as the specified speed of the movement of the specifictarget is higher, and when the specified speed of the specific target isequal to or higher than a set first threshold, sets, as the image light,pre-display image light generated on the basis of image data differentfrom the specific image light before setting the specific image light.22. A transmission type head mounted display device comprising: an imagedisplay unit including an image-light generating unit configured togenerate image light on the basis of image data and emit the imagelight, the image display unit allowing a user to visually recognize theimage light as a virtual image and transmitting an outside scene in astate in which the image display unit is worn on a head of the user; acontrol unit configured to set, as the image light that the control unitallows the user to visually recognize using the image display unit,specific image light generated on the basis of set specific image dataand changing according to elapse of time; and a movement specifying unitconfigured to specify speed of a movement of the user, wherein thespecific image data is set on the basis of specific information, thespecific image light includes a plurality of kinds of first image lightand second image light different from the plurality of kinds of firstimage light, the control unit changes the image light, which the controlunit allows the user to visually recognize using the image display unit,from the plurality of kinds of first image light to the second imagelight according to the elapse of time, and the control unit sets timefor changing the plurality of kinds of first image light to the secondimage light longer as the specified speed of the movement of thespecific target is higher.